Vinylidene chloride copolymers have found wide application in films, injection molded or vacuum formed articles, tubing or pipe, flat sheet and similar end uses. This wide variety of uses is due in part to the copolymers' fire retardant properties, such as low smoke generation and high limiting oxygen index. However, such copolymers have had limited use in low temperature application due to the loss of strength or toughness.
In the past, efforts have been made to reinforce vinylidene chloride copolymer compositions with additive formulations. For example, unsaturaed butadiene rubbers have been incorporated into the vinylidene chloride copolymer composition. While low temperature impact strength was improved, aging of these compositions brought about accelerated degradation of the rubber causing embrittlement. U.S. Pat. No. 3,240,743 shows an additive system of a saturated rubber latex which is physically blended with the vinylidene chloride copolymer.
The present invention is based on the discovery that a cross-linked polyacrylate rubber from specified monomers when incorporated into a vinylidene chloride copolymer composition in the manner herein-prescribed has a beneficial effect on low temperature toughness of the resultant polymer compositions.